Connection structure of coaxial cable

Abstract

A connection structure includes an external conductor of a coaxial cable which is electrically connected to a ground conductor installed at a surface of a planar circuit substrate, and an internal conductor of the coaxial cable which is connected to a micro strip line installed at the other surface of the planar circuit substrate. The internal conductor of the coaxial cable is welded to a conductive pattern of the micro strip line. The conductive pattern of the micro strip line includes a conductive welding portion welded to the internal conductor of the coaxial cable, a conductive landing portion extending from the conductive welding portion in a predetermined width, and an impedance converting portion whose width increases as it extends from the conductive landing portion.

What is claimed is:  
     
       1. A connection structure comprising: 
       an external conductor of a coaxial cable which is electrically connected to a ground conductor installed at a surface of a planar circuit substrate; and  
       an internal conductor of the coaxial cable which is connected to a micro strip line installed at another surface of the planar circuit substrate,  
       wherein the internal conductor of the coaxial cable is welded to a conductive pattern of the micro strip line, and  
       wherein the conductive pattern of the micro strip line comprises:  
       a conductive welding portion welded to the internal conductor of the coaxial cable,  
       a conductive landing portion that extends from the conductive welding portion in a predetermined width, and  
       an impedance converting portion whose width increases as the impedance converting portion extends from the conductive landing portion.  
     
     
       2. The connection structure of  claim 1 , further comprising at least one via hole which is formed in a predetermined pattern in the planar circuit substrate, surrounding the conductive welding portion, to guide signals transmitted from the coaxial cable. 
     
     
       3. The connection structure of  claim 2 , wherein at least two of the via holes are formed in a symmetrical pattern in the planar circuit substrate. 
     
     
       4. The connection structure of  claim 1 , wherein the conductive welding portion is circular. 
     
     
       5. The connection structure of  claim 1 , wherein the coaxial cable is vertically coupled with the planar circuit substrate. 
     
     
       6. The connection structure of  claim 1 , wherein the width of the impedance converting portion increases gradually as the impedance converting portion extends from the conductive landing portion. 
     
     
       7. A connection structure comprising: 
       an external conductor of a coaxial cable which is electrically connected to a ground conductor installed at a surface of a planar circuit substrate; and  
       an internal conductor of the coaxial cable which is connected to a micro strip line installed at another surface of the planar circuit substrate,  
       wherein at least one via hole is prepared in a predetermined pattern in the planar circuit substrate around the internal conductor of the coaxial cable coupled with a portion of the micro strip line; and  
       wherein a conductive pattern of the micro strip line comprises:  
       a conductive welding portion welded to the internal conductor of the coaxial cable;  
       a conductive landing portion extending from the conductive welding portion in a predetermined width; and  
       an impedance converting portion extending from the conductive landing portion with an increasing width.  
     
     
       8. The connection structure of  claim 7 , wherein at least two via holes are formed in a symmetrical pattern in the planar circuit substrate. 
     
     
       9. A connection structure comprising: 
       an external conductor of a coaxial cable which is electrically connected to a ground conductor installed at a surface of a planar circuit substrate; and  
       an internal conductor of the coaxial cable which is connected to a micro strip line installed at another surface of the planar circuit substrate,  
       wherein the internal conductor of the coaxial cable is welded to a conductive pattern of the micro strip line, and  
       wherein the conductive pattern of the micro strip line comprises:  
       a conductive welding portion welded to the internal conductor of the coaxial cable,  
       a conductive landing portion that extends from the conductive welding portion in a predetermined width,  
       an impedance converting portion whose width increases as the impedance converting portion extends from the conductive landing portion, and  
       a body portion which extends from an end of the impedance converting portion opposite the conductive landing portion and has a predetermined width.  
     
     
       10. The connection structure of  claim 9 , wherein a conductive pattern of the micro strip line comprises an impedance converting portion extending from the conductive landing portion with a gradually increasing width. 
     
     
       11. The connection structure of  claim 9 , wherein the width of the impedance converting portion increases gradually as the impedance converting portion extends from the conductive landing portion.